Editing Hen harrier

{{Short description|Species of bird}}
{{Speciesbox
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 13 November 2021">{{cite iucn |author=BirdLife International |date=2021 |title=''Circus cyaneus'' |volume= |page=e.T22727733A200497981 |doi=10.2305/IUCN.UK.2021-3.RLTS.T22727733A200497981.en |access-date=5 May 2025}}</ref>
| image = Circus cyaneus, Ballaugh Curragh, Isle of Man 1.jpg
| image_caption = Adult male
| image2 = Hen Harrier Pangolakha Wildlife Sanctuary Sikkim India Nov 2016.jpg
| image2_caption = An adult female from [[Pangolakha Wildlife Sanctuary]], [[East Sikkim]], [[India]]
| genus = Circus
| species = cyaneus
| authority = ([[Carl Linnaeus|Linnaeus]], 1766)
| range_map = Circus cyaneus distribution map.png
| range_map_caption = Range of ''C. cyaneus'' {{leftlegend|#02FF02|Breeding summer visitor|outline=gray}}{{leftlegend|#008000|Breeding resident|outline=gray}}{{leftlegend|#0080FF|Winter visitor|outline=gray}}
| synonyms = ''Falco cyaneus'' {{small|Linnaeus,&nbsp;1766}}
}}

The '''hen harrier''' ('''''Circus cyaneus''''') is a [[bird of prey]]. It breeds in [[Palearctic|Eurasia]]. The term "hen harrier" refers to its former habit of preying on free-ranging fowl.<ref name="RSPBHH">{{Cite web |title=Hen harrier |url=https://www.rspb.org.uk/discoverandenjoynature/discoverandlearn/birdguide/name/h/henharrier/ |access-date=2016-01-19 |publisher=RSPB}}</ref>

It [[bird migration|migrates]] to more southerly areas in winter. Eurasian birds move to southern Europe and southern temperate Asia. In the mildest regions, such as France and [[Great Britain]], hen harriers may be present all year, but the higher ground is largely deserted in winter.

The [[northern harrier]] was formerly considered to be a [[subspecies]] of the hen harrier.

==Taxonomy==
In 1758 the English naturalist [[George Edwards (naturalist)|George Edwards]] included an illustration and a description of the hen harrier in the first volume of his ''Gleanings of Natural History''. He used the English name "The blue hawk". Edwards based his hand-coloured etching on a bird that had been shot near London.<ref>{{Cite book |last=Edwards |first=George |url=https://www.biodiversitylibrary.org/page/56895915 |title=Gleanings of Natural History, exhibiting figures of quadrupeds, birds, insects, plants &c... |publisher=Printed for the author, at the College of Physicians |year=1758 |volume=1 |location=London |pages=33–34 Plate 225 |language=English, French |author-link=George Edwards (naturalist)}}</ref> When in 1766 the Swedish naturalist [[Carl Linnaeus]] updated his ''[[Systema Naturae]]'' for the [[12th edition of Systema Naturae|twelfth edition]], he placed the hen harrier with the falcons and eagles in the [[genus]] ''[[Falco (bird)|Falco]]''.  Linnaeus included a brief description, coined the [[binomial name]] ''Falco cyaneus'' and cited Edwards' work.<ref>{{Cite book |last=Linnaeus |first=Carl |url=https://www.biodiversitylibrary.org/page/445251 |title=Systema naturae : per regna tria natura, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis |publisher=Laurentii Salvii |year=1766 |edition=12th |volume=1, Part 1 |location=Holmiae (Stockholm) |page=126 |language=Latin |author-link=Carl Linnaeus}}</ref> The hen harrier is now placed in the genus ''[[Harrier (bird)|Circus]]'' that was introduced by the French naturalist [[Bernard Germain de Lacépède]] in 1799.<ref>{{Cite book |last=Lacépède |first=Bernard Germain de |title=Discours d'ouverture et de clôture du cours d'histoire naturelle |publisher=Plassan |year=1799 |location=Paris |page=4 |language=fr |chapter=Tableau des sous-classes, divisions, sous-division, ordres et genres des oiseux |author-link=Bernard Germain de Lacépède |chapter-url=https://books.google.com/books?id=6uhAAAAAcAAJ&pg=PA78}} Page numbering starts at one for each of the three sections.<!--BHL appears not to have a scan--></ref><ref name="ioc">{{Cite web |date=January 2022 |editor-last=Gill |editor-first=Frank |editor-link=Frank Gill (ornithologist) |editor2-last=Donsker |editor2-first=David |editor3-last=Rasmussen |editor3-first=Pamela |editor3-link=Pamela Rasmussen |title=Hoatzin, New World vultures, Secretarybird, raptors |url=https://www.worldbirdnames.org/bow/raptors/ |access-date=9 June 2022 |website=IOC World Bird List Version 12.1 |publisher=International Ornithologists' Union}}</ref> The genus name ''Circus'' is derived from the [[Ancient Greek]] ''kirkos'', referring to a bird of prey named for its circling flight (''kirkos'', "circle"). The specific epithet ''cyaneus'' is from [[Latin]] and means "dark blue".<ref>{{Cite book |last=Jobling |first=James A. |title=The Helm Dictionary of Scientific Bird Names |publisher=Christopher Helm |year=2010 |isbn=978-1-4081-2501-4 |location=London |page=[https://archive.org/stream/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling#page/n109/mode/1up 109], [https://archive.org/stream/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling#page/n126/mode/1up 126]}}</ref> The species is [[monotypic]]: no [[subspecies]] are recognised.<ref name=ioc/>

The hen harrier was formerly considered to be [[conspecific]] with the [[northern harrier]].<ref name=ioc/><ref>{{Cite journal |last1=Etherington |first1=Graham J. |last2=Mobley |first2=Jason A. |date=2016 |title=Molecular phylogeny, morphology and life-history comparisons within Circus cyaneus reveal the presence of two distinct evolutionary lineages |journal=Avian Research |volume=7 |issue=1 |pages=17 |doi=10.1186/s40657-016-0052-3 |doi-access=free}}</ref><ref>{{Cite journal |last1=Chesser |first1=R. Terry |last2=Burns |first2=Kevin J. |last3=Cicero |first3=Carla |last4=Dunn |first4=John L. |last5=Kratter |first5=Andrew W |last6=Lovette |first6=Irby J |last7=Rasmussen |first7=Pamela C. |last8=Remsen |first8=J.V. Jr |last9=Rising |first9=James D. |last10=Stotz |first10=Douglas F. |last11=Winker |first11=Kevin |year=2017 |title=Fifty-eighth supplement to the American Ornithological Society's ''Check-list of North American Birds'' |journal=The Auk |volume=134 |issue=3 |pages=751–773 |doi=10.1642/AUK-17-72.1 |doi-access=free}}</ref>

==Description==
[[File: Accipitridae - Circus cyaneus (male & female).JPG|thumb|240px|left|Circus cyaneus (male & female)]]
[[File:Hen Harrier Lungthu Pangolakha Wildlife Sanctuary East Sikkim India 08.11.2015.jpg|thumb|right|Bird in flight at an elevation of over 12,500 ft in [[Pangolakha Wildlife Sanctuary]] in [[East Sikkim]] district, [[India]] in the month of November]]

The hen harrier is {{convert|41|-|52|cm|in|abbr=on}}<ref name=hbw/> long with a {{convert|97|–|122|cm|in|abbr=on}} wingspan.<ref name=Mullarney/><ref name=RaptorsWorld/> It resembles other [[harrier (bird)|harriers]] in having distinct male and female plumages. The sexes also differ in weight, with males weighing {{convert|290|to|400|g|oz|abbr=on}}, with an average of {{convert|350|g|oz|abbr=on}}, and females weighing {{convert|390|to|750|g|oz|abbr=on}}, with an average of {{convert|530|g|oz|abbr=on}}.<ref name=hbw/><ref name=RaptorsWorld/> Among standard measurements, the [[Wing chord (biology)|wing chord]] is {{convert|32.8|to|40.6|cm|in|abbr=on}}, the [[tail]] is {{convert|19.3|to|25.8|cm|in|abbr=on}} and the [[Tarsus (skeleton)|tarsus]] is {{convert|7.1|to|8.9|cm|in|abbr=on}}.<ref name=RaptorsWorld/> It is relatively long winged and long tailed.<ref name=RaptorsWorld/>

The male is mainly grey above and white below except for the upper breast, which is grey like the upperparts, and the rump, which is white; the wings are grey with black wingtips. The female is brown above with white upper tail coverts, hence females, and the similar juveniles, are often called "ringtails". Their underparts are buff with brown barring.<ref name=hbw/> Juveniles resemble females but with less distinct barring, dark brown secondaries dark brown and less-barred belly.<ref>Woo-Shin Lee, Tae-Hoe Koo, Jin-Young Park (2005). A field guide to the birds of Korea. p. 106. {{ISBN|978-8995141533}}.</ref>

The female gives a whistled ''piih-eh'' when receiving food from the male, and her alarm call is ''chit-it-it-it-it-et-it''. The male calls ''chek-chek-chek'', with a more bouncing ''chuk-uk-uk-uk'' during his display flight.<ref name=Mullarney/>

==Behaviour==
This medium-sized [[Bird of prey|raptor]] breeds on [[moorland]], [[bog]]s, [[prairie]]s, [[farm]]land [[Western Gulf coastal grasslands|coastal prairies]], [[marsh]]es, [[grassland]]s, [[swamp]]s and other assorted open areas. A male will maintain a territory averaging {{convert|2.6|km2|sqmi|abbr=on}}, though male territories have ranged from {{convert|1.7|to|150|km2|sqmi|abbr=on}}.

These are one of the few raptorial birds known to practice [[Polygyny in animals|polygyny]] – one male mates with several females. Up to five females have been known to mate with one male in a season. A supplementary feeding experiment on the Orkney islands showed that rates of polygyny were influenced by food levels; males provided with extra food had more breeding females than 'control' males that received no extra food.<ref>{{Cite journal |last1=Amar |first1=A. |last2=Redpath |first2=S. M. |date=2002 |title=Determining the cause of the hen harrier decline on the Orkney Islands: an experimental test of two hypotheses |url=https://www.cambridge.org/core/journals/animal-conservation-forum/article/determining-the-cause-of-the-hen-harrier-decline-on-the-orkney-islands-an-experimental-test-of-two-hypotheses/787EF7FB5374E8CF8D8AE8D6D6B1EC51 |journal=Animal Conservation Forum |language=en |volume=5 |issue=1 |pages=21–28 |doi=10.1017/S1367943002001038 |bibcode=2002AnCon...5...21A |issn=1469-1795 |s2cid=85772194|url-access=subscription }}</ref>

The nest is constructed on the ground or on a mound of dirt or vegetation. Nests are made of sticks and are lined inside with grass and leaves. Four to eight (exceptionally 2 to 10) whitish [[Bird egg|eggs]] are laid. The eggs measure approximately {{convert|47|x|36|mm|in|abbr=on}}. The eggs are incubated mostly by the female for 31 to 32 days. When incubating eggs, the female sits on the nest while the male hunts and brings food to her and the chicks. The male will help feed chicks after they hatch, but does not usually watch them for a greater period of time than around 5 minutes.<ref name="Weidensaul1996" /> The male usually passes off food to the female, which she then feeds to the young, although later the female will capture food and simply drop into the nest for her nestlings to eat. The chicks fledge at around 36 days old, though breeding maturity is not reached until 2 years in females and 3 years in males.

In winter, the hen harrier is a bird of open country, and will then roost communally, often with [[Merlin (bird)|merlins]] and [[marsh harrier]]s. There is now an accepted record of [[Vagrancy (biology)|transatlantic vagrancy]] by the northern harrier, with a juvenile being recorded in [[Scilly]], [[Great Britain]] from October 1982 to June 1983.<ref name=BB2007/>

===Hunting behaviour===
This is a typical harrier, which hunts on long wings held in a shallow V in its low flight during which the bird closely hugs the contours of the land below it. Northern or hen harriers hunt primarily small [[mammal]]s, as do most harriers. Up to 95% of the diet comprises small mammals. However, [[bird]]s are hunted with some regularity as well, especially by males. Preferred avian prey include [[passerine]]s of open country (i.e. [[Old World sparrow|sparrow]]s, [[lark]]s, [[pipit]]s), small [[shorebird]]s and the young of [[waterfowl]] and [[Galliformes|galliforms]]. Supplementing the diet occasionally are [[amphibian]]s (especially [[frog]]s), [[reptile]]s and [[insect]]s (especially [[orthoptera]]ns).<ref name=RaptorsWorld/> The species has been observed to hunt [[bat]]s if these are available.<ref>{{Cite journal |last1=Mikula |first1=P. |last2=Morelli |first2=F. |last3=Lučan |first3=R. K. |last4=Jones |first4=D. N. |last5=Tryjanowski |first5=P. |year=2016 |title=Bats as prey of diurnal birds: a global perspective |journal=Mammal Review |volume=46 |issue=3 |pages=160–174 |doi=10.1111/mam.12060}}</ref> Larger prey, such as [[rabbit]]s and adult [[duck]]s are taken sometimes and harriers have been known to subdue these by drowning them in water.<ref name=RaptorsWorld/> Harriers hunt by surprising prey while flying low to the ground in open areas, as they drift low over fields and moors.<ref name=hbw/> The harriers circle an area several times listening and looking for prey. Harriers use hearing regularly to find prey, as they have exceptionally good hearing for diurnal raptors, this being the function of their [[owl]]-like facial disc.<ref name=RaptorsWorld/> This harrier tends to be a very vocal bird while it glides over its hunting ground.

===Mortality and competition===
Little information is available on the longevity in hen harriers. The longest-lived known bird is 16 years and 5 months. However, adults rarely live beyond 8 years. Early mortality is mainly due to predation. Predators of eggs and nestlings include [[raccoon]]s, [[skunk]]s, [[badger]]s, [[fox]]es, [[Corvus (genus)|crows and ravens]], [[dog]]s and [[owl]]s. Both parents attack potential predators with alarm calls and striking with talons. [[Short-eared owl]]s are natural competitors of this species, preferring the same prey and habitat, and having a similar geographic distribution. Occasionally, both harriers and short-eared owls will harass each other until the victim drops its prey and it can be stolen, a practice known as [[kleptoparasitism]]. Most often, the harriers are the aggressors, stealing prey from the owls.<ref name=owlpages/>

==Status==
This species has a wide geographical distribution and, although there is evidence of a population decline, it is not thought to be approaching the thresholds for the [[IUCN Red List]] criterion of population decline (i.e., a decline of more than 30% in ten years or three generations). It is therefore classified as "least concern".<ref name="iucn status 13 November 2021" /> However, in Britain and Ireland, hen harrier populations are in a critical state, mainly due to habitat loss and illegal shooting on [[grouse moor]]s.<ref name="RSPBHHL">{{Cite web |title=Welcome to the hen harrier LIFE project |url=http://www.rspb.org.uk/henharrierlife/ |access-date=2016-02-12 |publisher=RSPB}}</ref><ref>{{Cite web |title=Save the Skydancer |url=https://birdwatchireland.ie/henharrier/ |url-status=live |archive-url=https://web.archive.org/web/20240209085356/https://birdwatchireland.ie/henharrier/ |archive-date=2024-02-09 |website=[[BirdWatch Ireland]]}}</ref> There is sufficient suitable habitat to support over 300 breeding pairs of hen harriers in England alone, yet only 34 successful nests were recorded in 2022. Furthermore, many of the young birds do not survive beyond their first year, before the onset of sexual maturity at the age of two. Most UK Hen Harriers are found in Scotland, but even there the population declined by 27% between 2004 and 2016.

==Relationship with humans==
In some parts of Europe people believed that seeing a hen harrier perched on a house was a sign that three people would die. Unlike many raptors, hen harriers have historically been looked upon favorably by farmers because they eat predators of quail eggs and mice that damage crops. Harriers are sometimes called "good hawks" because they do not pose a threat to poultry as some hawks do.{{citation needed|date=October 2021}}

==Forestry and hen harriers==
[[File:Circus cyaneus MWNH 0850.JPG|thumb|Eggs, Collection [[Museum Wiesbaden]]]]
The hen harrier is a bird of open habitats such as heather moorland and extensive agricultural land. However, much of its range, particularly in Ireland and parts of western Britain, has been (and continues to be) afforested, mainly with non-native conifers such as [[Picea sitchensis|Sitka spruce]] (''Picea sitchensis'') from North America.<ref name=Barton2006/><ref name=Fielding2010/> Hen harriers nest and forage in commercial forestry plantations before the canopy closes (typically at  between 9 and 12 years old), but do not make much use of thicket and later growth stages,<ref name=Madders2000/><ref name=ODonoghue2004/> which typically comprise between {{frac|2|3}} and {{frac|3|4}} of the commercial growth cycle. Where afforestation replaces habitats previously used by hen harriers they will therefore tend to reduce overall habitat availability.<ref name=OFlynn1983/> However, where afforestation takes place in areas that were previously underutilised by hen harriers, it may increase the value of such areas to the species in the long-term.<ref name=Wilson2009/><ref name=Haworth2009/> Areas dominated by forestry may remain suitable to hen harriers provided that a mosaic of age classes is maintained within the forest so that areas of young, pre-thicket forest are always available.

==References==
{{Reflist|35em|refs=

<ref name="Barton2006">{{Cite journal |last1=Barton |first1=C. |last2=Pollock |first2=C. |last3=Norriss |first3=D.W. |last4=Nagle |first4=T. |last5=Oliver |first5=G.A. |last6=Newton |first6=S. |year=2006 |title=The second national survey of breeding hen harriers Circus cyaneus in Ireland |journal=Irish Birds |volume=8 |pages=1–20}}</ref>

<ref name="BB2007">{{Cite journal |last=Fraser |first=P.A. |display-authors=etal |year=2007 |title=Report on rare birds in Great Britain in 2006 |url=http://www.bbrc.org.uk/download/2006_report.pdf |journal=British Birds |volume=100 |issue=12 |page=707}}</ref>

<ref name="Fielding2010">{{Cite web |last1=Fielding |first1=A. |last2=Haworth |first2=P. |last3=Whitfield |first3=P. |last4=McLeod |first4=D. |year=2010 |title=Raptor species conservation frameworks: Hen Harrier framework project final report |url=http://robedwards.typepad.com/files/hen-harrier-framework-report-1.doc |publisher=Scottish Natural Heritage |location=Edinburgh}}</ref>

<ref name="Haworth2009">{{Cite book |last1=Haworth |first1=P.F. |title=An assessment of woodland habitat utilisation by breeding hen harriers |last2=Fielding |first2=A.H. |publisher=Scottish Natural Heritage |year=2009 |series=SNH Project No. 24069 |location=Edinburgh}}</ref>

<ref name="hbw">{{Cite book |title=Handbook of the Birds of the World |title-link=Handbook of the Birds of the World |publisher=[[Lynx Edicions]] |year=1994 |isbn=978-84-87334-15-3 |editor-last=del Hoyo |editor-first=J. |volume=2: New World Vultures to Guineafowl |location=Barcelona |editor-last2=Elliott |editor-first2=A. |editor-last3=Sargatal |editor-first3=J.}}</ref>

<ref name="Madders2000">{{Cite journal |last=Madders |first=M. |year=2000 |title=Habitat selection and foraging success of hen harriers (''Circus cyaneus'') in west Scotland |journal=Bird Study |volume=47 |issue=1 |page=32 |doi=10.1080/00063650009461158 |s2cid=85192594 |doi-access=free|bibcode=2000BirdS..47...32M }}</ref>

<ref name="Mullarney">{{Cite book |last1=Mullarney |first1=Killian |title=Collins Bird Guide |last2=Svensson |first2=Lars |last3=Zetterstrom |first3=Dan |last4=Grant |first4=Peter |publisher=HarperCollins |year=1999 |isbn=978-0-00-219728-1 |location=London |page=86}}</ref>

<ref name="ODonoghue2004">{{Cite thesis |last=O'Donoghue |first=B. |title=The Hen Harrier in Ireland |date=2004 |degree=Master's |publisher=University College Dublin}}</ref>

<ref name="OFlynn1983">{{Cite journal |last=O'Flynn |first=W.J. |year=1983 |title=Population changes of the hen harrier in Ireland |journal=Irish Birds |volume=2 |pages=337–343}}</ref>

<ref name="owlpages">{{Cite web |date=24 July 2013 |title=Short-eared Owl – ''Asio flammeus'' |url=http://www.owlpages.com/owls.php?genus=Asio&species=flammeus |access-date=1 December 2015 |website=owlpages.com}}</ref>

<ref name="RaptorsWorld">{{Cite book |last1=Ferguson-Lees |first1=J. |title=Raptors of the World |last2=Christie |first2=D.A. |publisher=[[Helm Identification Guides|Christopher Helm]] |year=2001 |isbn=978-0-7136-8026-3 |location=London}}</ref>

<ref name="Weidensaul1996">{{Cite book |last=Weidensaul |first=Scott |url=https://books.google.com/books?id=vnkpAQAAMAAJ |title=Raptors: the birds of prey |publisher=Lyons & Burford |year=1996 |isbn=978-1-55821-275-6}}</ref>

<ref name="Wilson2009">{{Cite journal |last1=Wilson |first1=M.W. |last2=Irwin |first2=S. |last3=Norriss |first3=D.W. |last4=Newton |first4=S.F. |last5=Collins |first5=K. |last6=Kelly |first6=T.C. |last7=O'Halloran |first7=J. |year=2009 |title=The importance of pre-thicket conifer plantations for nesting Hen Harriers (''Circus cyaneus'') in Ireland |journal=Ibis |volume=151 |issue=2 |page=332 |doi=10.1111/j.1474-919X.2009.00918.x}}</ref>
}}

==External links==
{{Commons category|Circus cyaneus}}
{{Wikispecies|Circus cyaneus}}
* [http://www.langholmproject.com/ The Langholm Moor Demonstration Project]
* [https://www.flickr.com/search/groups/?q=Circus%20cyaneus&w=42637302%40N00&m=pool Field Guide Page on Flickr]
* [http://www.irandeserts.com/content/%D8%AF%D8%B1%DA%AF%D8%A7%D9%87_%DA%A9%D9%88%DB%8C%D8%B1/%D9%BE%D9%88%D8%B4%D8%B4_%D8%AC%D8%A7%D9%86%D9%88%D8%B1%DB%8C/%D9%BE%D8%B3%D8%AA%D8%A7%D9%86%D8%AF%D8%A7%D8%B1%D8%A7%D9%86_%D8%A7%DB%8C%D8%B1%D8%A7%D9%86/%D9%BE%D8%B1%D9%86%D8%AF%DA%AF%D8%A7%D9%86_%D8%B1%D8%A7%D8%B3%D8%AA%D9%87_%D8%B4%D8%A7%D9%87%DB%8C%D9%86_%D8%B3%D8%A7%D9%86%D8%A7%D9%86/%D8%B3%D9%86%D9%82%D8%B1_%D8%AE%D8%A7%DA%A9%D8%B3%D8%AA%D8%B1%DB%8C.htm Range in Iran] (in Persian)
* [https://web.archive.org/web/20160305010012/http://aulaenred.ibercaja.es/wp-content/uploads/113_HenHarrierCcyaneus.pdf Ageing and sexing (PDF; 4.3 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze]
* {{InternetBirdCollection|hen-harrier-circus-cyaneus}}
* [http://www.rspb.org.uk/discoverandenjoynature/discoverandlearn/skydancer/ RSPB Skydancer website] {{Webarchive|url=https://web.archive.org/web/20161003054126/http://www.rspb.org.uk/discoverandenjoynature/discoverandlearn/skydancer/ |date=2016-10-03 }}
* {{BirdLife|22727733|Circus cyaneus}}
* {{Avibase|name=Circus cyaneus}}
* [https://birdwatchireland.ie/henharrier/ Save The Skydancer page] on [[BirdWatchIreland.ie]]

{{Taxonbar|from=Q25572|KNSL=yes}}
{{Authority control}}

{{DEFAULTSORT:harrier, hen}}
[[Category:Harriers (birds)|hen harrier]]
[[Category:Birds of prey of Eurasia]]
[[Category:Birds described in 1766|hen harrier]]
[[Category:Taxa named by Carl Linnaeus|hen harrier]]